Crystal mounting



Patented Nov. 13, 1923.

UNITED STATES WALTER M. SCOTT, 0F CLEVELAND, OHIO.

CRYSTAL MOUNTING.

Application filed December 10, 1919. Serial no. 343,840.

T 0 all whom it may concern:

Be it known that I, WALTER M. Soo'rT, a citizen of the United States 7 residing at Cleveland in the county of duyahoga and State of (lhio, have invented a certain new and useful Improvement in Crystal Mountings, ofwhich the following is a full, clear, and exact description, reference being had to the accompanying drawings.

a This invention relates to mountings for holding in place the crystals or observationglasses .ofmeters, gauges, and other instruments or devices. The objects of the invention are the provision of a securing device which shall hold the glass or other closure with great rigidity and-in liquid-tight manner but without threading, beading or other mechanical manipulation of the mounting; the provision of a crystal securing device which will hold the crystal with great posi- I tiveness against accidental removal but which by proper means can be removed without breakage of any part; the provision of a device of this character which shall be cheaper to make and simpler to use than other devices; while further objects and advantages of the invention will become apparent as the description proceeds.

In the drawing accompanying and forming a part of this application I have shown one embodiment of my said invention, although itwill be understood that this drawing is illustrative only and does not limit me to the particular construction therein shown. In this drawing, Fig. 1 is a sectional view through my improved crystal mounting; Fig. .2 is a perspective View a showing the inner and outer rings separated from each other;,Fig. 3 is a sectional view through one type of measuring instrument 'in connection with which my improvements may be used; and Fig. 4 is a diagrammatic view showing the force action.

Describing'the parts by reference characters, 1 represents generally the outer ring which is essentially characterized by the possession of an internal cylindrical portion 2 in which the crystal 3 is received, said recess having at one end an inwardly projecting flange't against which the crystal is seated. In many aspects of my invention it is immaterial what form is taken by the V remainder of this outer ring although in the resent instance I have shownthe same as ormed outside of this recess with a flat 01rvery slightly flared wall portion 10 having at its end of smaller diameter the inwardly projecting flange 11 which also makes a slight inclination with the plane of the ring. This inner ring is made of one piece of metal, unsevered at any point and of a diameter to' fit very snugly in the recess 2. The thickness of the metal from which this ring is made is so chosen as to afford a certain amount of flexibility wherefore it will be seen by reference to Fig. 4E that each infinitesimal segment of the ring constitutes a bent lever of which the point f constitutes the fulcrum, and that a downwardly acting force at P will be transformed into an outwardly acting force at W.

The rings and crystal are assembled by means of a suitable punch and die which act upon the two rings equally so as to force the same into close contact with each other, whereupon the first portion of the inner. ring to come into contact with the cystal is the top of the flange 11 which thereby tends to rock downwardly and to force the side wall of the ring outwardly, as a result of which the device. retains its place with great permanence and any force tending to unseat the crystal enhances the tightness with which it is held. In some instances, as in electric measuring instruments, the rings can be dipped in enamel, paint, varnish,lacquer,japan or the like and the same will increase the tightness, although tight joints can be made without any such reenforcement. In Fig. 3 I have shown my improved mounting in connection with an electric measuring instrument of the type known as a dash-board ammeter for automobiles and comprising a dial 12, pointer 13, armature 14 and current coil 15, the whole being enclosed in a cylindrical casing 16 whose forward end is formed with an attaching flange 17 which fits against the portion 6 of the outer ring inside its lip 7.

The parts are then held together by bending the flanges 6 and 17, and also between the crystal 3 and one or both of the flanges between which it lies. 1

In order to remove the crystal, it is necessary to employ a die which will hold the outer ring securely, in combination with a punch which will engage the crystal at all points clear to the edge of the flange 4:, whereupon a steady pressure will ordinarily disfilace the inner ring without breakage.

aving, thus described my invention what I claim is 1. In a device of the character described, in combination, an outer ring having a cylindrical recess terminated by an inward shoulder a transparent plate in said recess and positioned by said shoulder, and an endless elastic metal inner ring of a cross section slightly morethan rectangular, said inner ring having the extremities of its side Wall tightly wedged in said recess and having an unbroken continuous inturned flange pressed against the opposite side of said plate from said shoulder.

2. In a device of the character described, in combination, an outer ring having a cylindrical recess terminated by an inward shoulder, a closure late in said recess and positioned by said s oulder, andan endless elastic metallic inner ring having a slightly flaring side wall, the larger end of which fits tightly inside said recess and also having having at its narrower margin a flange turned inwardly to an amount less than perpendicular to the recess wall, the inner edge of said flange being pressed against said plate.

4. As an article of manufacture, an outer ring having a cylindricalrecess adapted to receive a crystal and having at one end an inwardly projecting flange, andv an endless inner ring of slightly elastic metal having a. side wall adapted to fit frictionally into said recess and also having a flange adapted to oppose said first flange, said last flangehaving an uninterrupted inner margin and also having its upper surface slightly beveled whereby said inner margincomes first into contact with said crystal. I

In testimony whereof, I hereunto 'afix my signature.

WALTER M. SCOTT. 

